And alfred j



(llodeL) J. A. SMITH 8a A. J. ATHAY.

OBJECT LENS FOR TELESGOPES AND CAMERAS. No. 318,666. 7 Patented May 26, 1885.

I curvature of a solid lens of the diameter desired, so that each part A A is the segment JAMIE A. SMITH, OF DECORAH, IOWA, AXD ALFRED J. LAND, ILLINOIS.

ATHAY, 0F sesaoeascr-taus roe 'ri-zusscoprs mo CAMERAS..-

BPECII'ICA'I'IOR forming part of Letters Patent No. 318,866, dated May 26. 1885.

' Arplieafio. me (new: mac model.)

To all whom it may concern: Be it known that we, Janus A. SnI'rH, of Deoorah, in the county of Winneshiek and State of Iowa, and Amman J. Artur, of Sparland, in the county of Marshall and State 0 Illinois, have invented a new and useful Improvement in Object-Lenses for Telescopes- ,lndjhmeras, of which the following is a full,

clear, and exact description. [0 Our invention has a twofold object, first, to obtain the efl'ect of a lens of large diameter without the labor and expense required for the production of large lenses; and, second, to improve photographic pictures by the use of 5 lensesconstructed according to our-invention, and which serve to intensify the image and produce a stereoscopicefl'ect in the picture. To these ends we construct a lens of compound or double form, each portion of the lens being :0 ground to the curvature of a solid lens of the required diameter, and the two parts of the lens being held in their support soas to be retained in the same relative position with regard to each other as they would sustain in a '25 solid lens of the same diameter and curvature. Reference is to be had to the accompanying. drawings, forming a part of this specification, in which similar letters of reference indicate corresponding parts in all the figures. Figure 1 is a section of our improved lens,

, shown in the form adapted fig. Zshows the same as applied to a telescope. Figs. 3and 5 represent modifications in the construction. Fig. 4 shows a format 5 mounting the lens. Referring to Figs. 1 and 2, A A are the two I parts of the compound lens. These are constructed by securing twodisks of glass in the same plane and then grinding them to the of a solid lens. These are then secured or set in a frame of suitable character, so as to obable material and for the camera. 7

The frame or setting may consist of any suitbe made of any suitable form; but the material must besnch as will be but little affected by heat, cold, or dampuess. For telescopes the setting may be of 5o some inferior glass, or the setting may be, as shown in Fig. 4, similar tothose used in operaglases. The same efl'ect and result may be obtained by taking an ordinary lens,'and by diaphragnis or other means rendering it opaque, except at diametrically-opposite portions, as shown in Figs. 3and 5, those portions being equivalents of the sections or parts A A before described. By this construction the eflect of a lens of any diameter may be produced at much less expense of time and labor than would be required for the production of a solid lens of the same diameter. The image produced at the common focus of the two seotions of the lens will-give a ph'tographic pic- 0 ture of superior character.

It is to be understood that in cameras this construction applies tothefront or object lens, the condensing-lens being applied as usual.

Having thus described our invention, we claim as new and desire to securc'by Letters Patent- A lens for telescopes, cameras, &c., consisting of two separated transparent sections of a lens of a given diameter, which sections are 7 5 spaced from each other such a distance that the exterior surfaces of the convex portions are concentric, and the inner surfaces of the convex portions are also concentric with each other, substantially as set forth. 7

' JAMES A. SMITH. ALFRED J. ATHAY. W'itumse's to the signature 'of James A. r Smith:

C. A. Moonr, Josnrn Sxrru.

Athay:

"1 tin their proper relative positions in regard -45 weachother.

. W. D. De Koanunm, N. W. Tamera. g

Witnesses to the signature of Alfred J.- I 

